HVO 2009 Annual Environmental Management Report - Final

Coal & Allied – Hunter Valley Operations
3.2.2 Environmental Performance
Depositional Dust
To monitor regional air quality, HVO operated and maintained a network of 10 depositional dust gauges on
private land. Depositional dust was monitored monthly in accordance with AS 3580.10.1 (2003) – (Methods
for Sampling and Analysis of Ambient Air – Determination of Particulates – Deposited Matter – Gravimetric
Method). Sites were analysed for mass, total insoluble matter and ash.
Annual Average Assessment
Table 17 and Figure 20 show the average depositional dust results for 2009 compared with the depositional
dust impact assessment criterion of 4g/m 2 /month (annual average for total insoluble solids). During 2009 all
sites complied with the criteria.
Depositional dust gauges located on Coal & Allied owned mining land provide additional information for the
dust management at HVO. A dust isopleth (Figure 22) shows the average depositional dust results for 2009 at
all gauges.
An additional impact assessment criterion of a maximum increase of 2g/m 2 /month annual average for total
insoluble solids applies to HVO depositional dust. The normal intention of this criterion is to limit the increase
in dust deposition from the pre-mining situation to the levels that apply when mining has commenced. As
there are no instruments available to distinguish the dust contributed by the mine compared with the dust from
other sources, environmental performance against this condition cannot comprehensively be tested via the
monitoring programme. Results indicated that this condition was complied with in 2009 (Figure 21). However,
most sites reported an increase in dust levels from the previous results, with the exception of D118, DL14 and
Warkworth School. This conceivably is the result of lower than average rainfall for 2009 compared with 2008.
Data recovery for the 10 dust deposition gauges was 98 per cent. Two samples were unable to recover data
due to broken dust deposition bottles.
A number of the samples were contaminated by material or various activities that may have altered the results
from a true reading of dust deposition. Contamination was assessed based on field observations, laboratory
analysis, mine activities, historical data and wind patterns. Samples can include organic material such as bird
droppings, insects and vegetation. Insoluble solids may have been from a localised non-mine source such as
livestock or farm activities. Therefore, results may not be representative of mining’s contribution to dust
deposition. High monthly results (ie >4g/m 2 /month) are summarised in
Table 18. Depositional dust data is provided in Appendix 6.
AEMR 2009 57